//
// Security.cs
//
// Author: najmeddine nouri
//
// Copyright (c) 2013 najmeddine nouri, amine gassem
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
//
// Except as contained in this notice, the name(s) of the above copyright holders
// shall not be used in advertising or otherwise to promote the sale, use or other
// dealings in this Software without prior written authorization.
//
﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Security.Cryptography;

namespace Badr.Server.Middlewares
{
    internal static class Security
    {
        internal static RNGCryptoServiceProvider _RNGCryptoServiceProvider = new RNGCryptoServiceProvider();

        internal static string GenerateId(int length = 15)
        {
            if (length > 0)
                return Convert.ToBase64String(GenerateBytes(length));

            return null;
        }

        internal static byte[] GenerateBytes(int length = 15)
        {
            if (length > 0)
            {
                byte[] data = new byte[length];

                lock (_RNGCryptoServiceProvider)
                    _RNGCryptoServiceProvider.GetBytes(data);

                return data;
            }

            return null;
        }

        internal static string GenerateSalt(int iterations = 1000)
        {
            if (iterations < 1000)
                return null;

            return Convert.ToBase64String(GenerateBytes(12));
        }

        internal static string Hash(string value, string salt, int iterations = 1000)
        {
            using (var pbkdf2 = new Rfc2898DeriveBytes(Encoding.UTF8.GetBytes(value), Convert.FromBase64String(salt), iterations))
                return Convert.ToBase64String(pbkdf2.GetBytes(24));
        }
    }
}
